MEANS FOR CLAMPING A FILTER MEDIUM TO A SUPPORTING FRAME

Abstract: An arrangement in air treatment plants and comprising a frame (2), a filter connectable with the frame (82) and a casing, which is meant to reach around the filter. The frame (82) shows holding means (5) for holding the filter to the frame. The holding means (5) comprise pivotable fastening arms (7), which are arranged to be able to be pivoted towards a flanging (9) extending from the opening (10) of the frame (2) and towards a surface of the frame. Said surface is meant to be turned towards the filter. The filter is anchored to the frame (2) by squeezing between the fastening arms (7) and the flanging (9). The filter is provided with stiffenings, partly in form of individual elements, partly produced by influence of the filter material by means of heat and pressure. The said casing is provided with closing devices permitting that a consumed filter can be wrapped up by the casing in such a way that the casing fits tight around the filter.

Description: MEANS FOR CLAMPING A FILTER MEDIUMTO A SUPPORTINGFRAME The present invention relates to an arrangement in air treatment plants and/or climate plants showing insta "1 lation devices for holding filters or one or more frames for filters. The arrangement comprises a frame, a filter connectable with the frame and a casing, which is meant to reach around the filter. There is a need of a simpler and more reliable way to obtain an intended quality of air in air treatment and climate plants and which way secures the settled separation degree of contaminations in that contamined air which will be filtrated or cleaned and perhaps for re-circulation in the air treatment system. Another need is that in a satisfactory way be able to handle a filtering device used in the plant and in a safe and from an environmental point of view acceptable way be able to take charge of a contamined and used filter in the plant from the place of use and to depositing or destruction. A further need, which generally exists in devices, is to be able to reduce the cost of a device, decrease the consumption of material and/or to shape the device in such a way that it at least to some extent is re-utilizable. The filtering material itself cannot be at issue for re-utilization but has to be taken charge of and in applicable cases be neutralized, especially when used in plants which are installed in such environments where harmful or extremely dangerous materials, particles, dusts and the like exist or can exist in that air which will be subjected treatment. Hospitals and nuclear power plants are examples of such environments. When handling known arrangements of the kind in question, for example when a filter is exchanged, the person has to grab the dirtied or used filter consequently entailing risks. Furtherπiore, the person make the new, clean filter contamined when mounting the filter and all the rest which is touched in that exemplified exchange of filter. In addition, it exists often leak flows of that air, which is going to be filtered and in that respect between the filter media itself and that holding device in the form of a stabilizing element, the so-called filter-frame, which holds the filter media in an air treatment and/or climate unit in the plant, as well as between the filter-frame and that device, in which the filter-frame is mounted and also between filter-frames, when more such are used for covering the area of air flow in question. A known device, consisting of a filter which is fixed to the filter-frame, one has been successful in reducing or eliminating the risk for leak flows between filter and frame. However, the problem with leak flows remains around the frame and between them, when two or more are used together. Moreover, there exist series of other inconveniences in this known device resulting in that the device cannot be handled and be taken charge of in a safe and from environmental point of view satisfactory way and neither can be re- utilized concerning these parts, which does not need to be deposit or subject for destruction. The frame is shaped of thin metal which is folded to a frame which thereby gets sharp or keen edges and corners. Furthermore, the frame requires reinforcements, which are made of an inside frame and rods of metal extending across the inside frame. Notwithstanding that fact the frame has low stability and strength jeopardizing the intended functioning of the device and filter and the degree of separation. In addition, the frame must during transportation and installation be handled carefully in order that the frame would not be broken or at least be deformed and by that unfit for use. When a filter has been consumed not only the filter can be rejected but also the frame must be rejected, as well as the said inside frame with the bars. The bars have also in view to form stays for the filter for staying of the filter. The frame is proportionately heavy. In order to reduce spreading of dust, particles and the like from the contamined filter and by that the risks of infection and contamination, the device can be wrapped up in a plastic bag after has been taken out from the unit. By the existance of the metal frame and the sharp edges there exists risk for that that the wrapping is penetrated during handling and transportation. It should be noted that the contamin¬ ated device is handled concerning a used filter without any protecting wrapping until that the device is placed in an eventual wrapping. Such a frame, which is used only once, is thus of financial reasons shaped with low strength and quality. The cost for such a frame is still not advant¬ ageous as it takes up large volume during transportations and when it is deposit. Filters of the kind in question must be provided with stiffening means so that the filter adopt intended shape and function. Besides an increased cost for the filter such means cause unnecessary assembly work. The known devices and filters cannot be handled satisfactory which is not only unsatisfactory but unacceptable in purification of air from noxious or other dangerous components, as, for example, bacteria, radioactive particles, toxic substances, etc. When a device or a filter, for example, is going to be exchanged, it must be done in such a way that, that staff, who are going to handle the device and effect the exchange of the filter sufficiently can be protected from the contaminated or infected filter. An arrangement in accordance with the invention, which is used in the process referred to, can, with regard to this part of an air treatment and/or climate plant, fulfil the requirements made, while at the same time the disadvantages of known arrangements and filters are eliminated. Thus, one object of the present invention is to effect a simpler and more reli¬ able procedure in air treatment and/or climate plants in connection with filtration of air and which can ensure the intended quality of that air having been led through an arrangement according to the invention, which is an integral part of an air treatment and/or climate unit. This object is fulfilled i.a. by that fact that the arrangement can be arranged in the existing area of air flow without that any leak flows appears around the arrangement or the arrangements and in that respect also between the arrangements, as two or more arrangements can be arranged together for covering the said area of air flow. Further by that fact that the filter can be arranged tight-fitting with that element, which holds and stabilizes the filter, or the so-called filter-frame. Due to the shaping of the arrangement, there is no need for stabilizing rods, stays or similar for the filter, which obstructs or hinders the air flow. In addition, the arrangement according to the invention comprises i.a. a particular shaping of the filter, which does not need arranged metal rods for stiffening of the filter, so notwithstanding the lack of such rods the filter has more stability in shape, can be shaped with larger filterarea and resulting in that the stream of air flow through the filter is facilitated compared with the current filters of the kind in question. Another object is to effect conditions for a safe handling of contamined and used filter from that it is going to be taken out of the unit and to depositing or destruction. This is carrying out by that the arrangement or filter is provided with a casing already when it is installed in the unit and which casing is shaped in such a way that it is easy to handle when enclosing the contamined filter, that the enclosing can be carried out without that the contamined parts of the arrangement or filter need to be touched and that the casing can be closed tightly. For accessibility to the arrangement when a contaminated and used filter is exchanged and when it is unfasten from the frame, the arrangement comprises a handle and/or a mechanism in form of holding means, which can comprise handles or the like, which can be arranged protruding from the arrangement, be arranged to extend outside the arrangement itself and/or be arranged so that they will not exist in the said area of air flow where impure air flows. Trans¬ port, keeping and the like of the contamined and used filter from the removal from the unit and to depositing or destruction is done within the tight casing. Thar wrapping with filter forms a minimal volume when the filter is separated from the frame and no or principally no exterior means exist supplied to the filter for holding its form. An additional object with the present invention is to effect a re-utiliz- able frame, i.e. that it is shaped in such a way, that a filter can be connected with the frame under satisfactory tight-fitting with the frame and that the filter when exchanged in a simple way can be unfasten from the frame. By such a shaping of the arrangement, the stabilizing element for the filter or the frame can be shaped with satisfactory strength and quality and be provided with sealing elements for lying against the unit surrounding the arrangement and between the arrangements, when two or more such are used together, and which with higher quality and shaping in an improved and safer manner prevents leak flows. The arrangement in accordance with the invention is thus characterized in that the frame shows holding means to hold and/or anchor the filter to the frame. Further, that the filter is provided with stiffenings and the casing with closing devices. In an embodiment of the arrangement in accordance with the invention the frame shows surfaces turned towards the filter and the holding means are arranged to run as tightening means along the surfaces, whereby the hold¬ ing means comprise fastening arms which are pivotably arranged. According to another embodiment of the arrangement in accordance with the invention a flanging extends from the opening of the frame and in the direction of that surfaces of the frame, which are turned towards the filter. In an additional embodiment of the arrangement in accordance with the invention the said holding means or fastening arms are arranged to be able to be pivoted in the direction of the said flanging and by that anchor the filter to the frame by squeezing between the fastening arms and the flanging. According to yet another embodiment of the arrangement in accordance with the invention the holding means comprise legs or arms, whereby at least one leg or arm is arranged to extend in the arrangement or the holding means so a prestressing is attained. In yet an additional embodiment of the arrangement in accordance with the invention the filter shows pockets, which are provided with stiffenings arranged by influence of the filter media by means of heat and pressure. According to another erribodiment of the arrangement in accordance with the invention one end part of the filter is provided with stiffenings in form of individual elements or angular means. In an additional embodiment of the arrangement in accordance with the invention the casing shows a first opening and a second opening, which openings are located in the end parts of the casing. Said end parts show closing devices. Further that the filter shows a first end part, which is arranged with or shows a border, to which stiffenings are arranged at a distance from one another. Preferably, four stiffenings are arranged and in the same distance with one another. According to yet another embodiment of the arrangement in accordance with the invention the said closing devices comprise one or more closing cords or similar, which are arranged to run in the casing or through perforat¬ ions arranged in the casing. In yet an additional embodiment of the arrangement in accordance with the invention the side-edge or circumference edge is provided with holding elements in order to take up a sealing element, for example in the shape of a so-called O-ring, and which runs around the circumference of the frame. According to another embodiment of the arrangement in accordance with the invention the casing is connected with the filter, preferably by that fact that a part of the casing is attached to the filter. In an additional embodiment of the arrangement in accordance with the invention the casing shows a length exceeding or substantially exceeding the length of the filter and the casing is connected with the filter some distance from one end part of the filter, whereby some part of the casing can be folded back over the casing or the filter when the filter is arranged to the frame. According to yet another embodiment of the arrangement in accordance with the invention the casing is arranged in the arrangement or with the filter in such a way that the casing guides the air flow towards the filter when a frame with a filter is arranged in an installation device in an air treatment plant. Further characteristics of and advantages with the arrangement in accord¬ ance with the invention will in the following description of the invent- ion be apparent by embodiment exaπples, whereby a simultaneous reference will be made to the accompanying schematic drawings, of which Fig. 1 shows a perspective view of a part of an arrangement in accordance with the invention and a frame, which is included in the arrangement according to the invention but shown without i.a. holding means, whereby the figure will illustrate that the arrangement or the frame can be supplied to a plant or its installation device for a filter or similar, Fig. 2 shows from one side the frame shown in Fig. 1, however without the sealing elements shown in Fig. 1, Fig. 3 shows a frame according to one embodi¬ ment of the arrangement in accordance with the invention and with holding means and in one position or tighten position, however without any filter, Fig. 4 shows in a perspective view one embodiment of a filter, Fig. 5 shows in a perspective view a part of a filter according to another embodiment and in that respect provided with stiffening elements, from which one is evident from the figure and according to one embodiment, Fig. 6 shows from above a part of the arrangement and in accordance with one embodiment, whereby the part comprises a filter and a casing arranged with the filter, Fig. 7 shows a sectional view of a frame part according to a third embodiment, Fig. 8 shows a cross-section of a frame part according to a fourth embodiment, Fig. 9 shows in a perspective view a part of a frame as previous shown or shown in Fig. 3 or according to a fifth embodiment and in a second position or open position, Fig. 10 shows a cross-section of a frame part according to a sixth anbodiment, Fig. 11 shows a cross-section of a frame part according to a seventh embodiment. Fig. 12 shows in a section I - I in Fig. 13 a part of a frame according to an eighth embodiment and with a connected filter, Fig. 13 shows from above a part of a frame or the part of the frame according to Fig. 12 and Fig. 14 shows a part of a casing with a part of a closing device according to one embodiment and which shall be arranged in the casing in both end parts of the casing. The reference designation 1 in Fig. 1 shows schematically an installation device in that plant or unit, in which the arrangement according to the invention is going to be arranged. The arrangement, which in the figure is shown in form of only a part of a frame 2, can be arranged to be pushed into the installation 1, which can be in form of or comprise guides, holding bands or similar. The arranganent, which is going to be supplied to the installation device 1, comprises besides the said frame 2 also a filter 3, see for example Fig. 4, and a casing 4, see Fig. 6. The frame 2 makes a holding device and a stabilizing element for the filter 3. Further, the frame 2 shows an opening 10, which is bordered by a flange 20, which pass into a flanging 9 turned towards the frame 2 or a surface 11 shown by the frame and the free edge 19 of the flanging ends above the said surface 11, see also for example Figs. 2, 7, 8, 10 and 11. The flang¬ ing 9 extends at an angle towards the frame 2 and forms a hold for the filter 3 or is included as a part of a holder for the filter. The flanging 9 stretch the filter 3 and holds the filter in the stretched position and by that effect i.a. the intended inlet opening into the filter for that air, which is going to be treated, purified or similar. The said flange 20 in the opening 10 of the frame 2 sets the inlet opening in the arrange¬ ment. In the edge 12 or circumference surface of the frame 2 is arranged holding elements 22 for sealing elements 21, see also Fig. 12. The sealing elements 21 can Consist of one or more parallelly extending O-rings of silicone, rubber, an elastic or similar. The sealing element 21 is meant for tighten against these means limiting the area of air flow and in these cases two or more arrangements or frames are arranged in order to together cover that area of air flow, tighten against adjacent arrangements or frames 2. The frame 2 comprises a frame profile 14, for example in form of a square tube of steel or an aluminium profile with the said flange 20 and flanging 9. With further reference to Figs. 3 and 9 it is evident that the frame is provided with holding means 5, comprising fastening arms 7 or similar. The holding means 5 are supported pivotally with the frame 2 by links 8 or axes, for example in form of screws, rivets or similar. As it is evident from, for example Figs. 3 and 7, the frame 2 can show ears 6 or similar extending from the said surface 11 of the frame 2 and in which the holding means 5 are pivotably supported. The holding means 5 comprise, according to the embodiments shown, a L-shaped profile 15, 17 extending at a distance from said surface 11 of the frame 2 and the said flanging 9 and around the extension of the flanging. The one leg 15 in the L-shaped profile of the holding means 5 extends in the direction from said surface 11 of the frame 2 and parallelly or substantially parallelly with the said flange 20 in the opening 10 of frame 2, while the other leg 17 in the L-shaped profile of the holding means 5 extends in the direction towards the flanging 9, however leaving a slot 13 between the second leg 17 and the flanging 9, and parallelly or substantially parallelly with the said surface 11 of the frame 2. The filter 3 shall extend into the frame 2 in the said slot 13 for anchoring in the frame 2 by squeezing between the holding means 5 and the flanging 9. According to one embodiment of the frame 2 or the holding means 5, the holding means are shaped in two parts or as two U-shaped parts 24 with a web 25 and legs 26, 27 and made of, for example, sheet-metal or in form of angle steel, see the embodiment of the frame 2 shown in Figs. 3 and 9. At this it is evident that the frame 2 from a closed position or a posit¬ ion where the frame is meant to anchor the filter 3 to the frame 2 by squeezing according to Fig. 3, can take an open position according to Fig. 9, whereby the holding means 5 are turned out from the frame 2. At this it is also evident that the holding means 5, the fastening arms 7 or the legs 27 of the holding means 5 can be used as supporting legs 28 for the frame 2, when the frame or the arrangement is going to be handled prior the arrangement into the installation device 1 or after has been taken out from the installation device 1. It is further evident that the legs 21 of the holding means 5 or the two U-shaped parts 24 can be arranged to extend under another angle than the legs 26 of the holding means 5. This because of obtaining a prestressing of the legs 27 for an improved anchoring and connection of the filter 3 to the frame 2 in that part of the frame owing to the fact that the legs' 26 tight-fitting and squeezing of the filter 3 between the legs 26 or fastening arms 7 in this part of the holding means 5 and the flanging 9 is ensured by a locking device 23, which is arranged to engage with the legs 27 and keep the hold¬ ing means 5 in a tight or closed position of the frame 2 or the filter 3 in a holding position by the frame 2. In order to facilitate the handling of the arrangement, for example when it is introduced or taken out from the installation device 1, or the handling of the holding means 5, the holding means 5 show gripping parts 16, for example in form of handles 16, which are arranged to the legs 26 according to the embodiments. The locking devices 23 can consist of one or more tongues 29, legs or the like with an ridge 39, bent edge in the tongue or the like, behind which the holding means 5 or its said leg 26 or fastening arm 7 can be brought to spring for squeezing the filter 3 between the holding means 5 and the flanging 9. For unfasten of the filter 3 and opening of the frame 2, the tongue 29 in the locking device 23 is brought at this to be removed from the holding means 5 or its leg 26 or the fastening arm 7 against the force of the spring of the locking device 23 or its tongue 29. For simple handling of the arranganent there exists according to one embodiment of the arranganent only one locking device 23 with two tongues 29 or the like each for engagement with one leg 26 of the holding means 5 - one tongue engages one leg 26 of one part 24 in the holding means 5 consist¬ ing of two U-shaped parts and the other tongue 29 engages the leg 26 of the other part 24 of the holding means 5. By means of the engagement of the locking device 23 with the said legs 26 or parts of the holding means 5, it is secured that the holding means 5 anchor the filter 3 to the frame 2 at these and adjacent parts in an intended way. For an improved anchoring of the filter 3 or ensuring its anchoring between the holding means 5 and the flanging 9 in the frame 2 in these parts, which are situated far from the locking device 23 or its tongues 29, i.e. according to the embodiment example at the opposite located or extending legs 27 in the holding means 5, these legs 27 or parts of the fastening arms 7 can be arranged prestressed. Such a prestressing is effected, for example, by that fact that one lets the legs 27 extend in another or divergent angle with regard to the remaining parts of the fastening arms 7 in the holding means 5 when the holding means 5 or the parts 24 of the holding means 5 are designed so when the frame 2 is closed the said prestressed legs 27 will reach the filter 3 before the remaining parts of the fastening arms 7 reach the filter 3. Besides or instead of a prestressing of the legs 27, a spring loaded hook or similar can be arranged to extend in the inter¬ space between the legs 27 of the two U-shaped parts 24. As it is evident from, for example Figs. 7 and 10, so extends the second leg 17 in the L-shaped profile of the holding means 5 on a level some lower than the highest level or position of the flanging 9 or the flange 20, i.e. that the said second leg 17 with satisfactory margin will squeeze the filter 3 between the holding means 5 and the flanging 9 or its contact surface 49 extending towards the holding means 5. In an embodiment of the holding means 5 or of its second leg 17, the free end part 48 of the second leg 17 is arranged to extend at an angle to the extension of the rest of the extension of the second leg 17, whereby the second leg 17 is arranged with an angled part towards the flanging 9 or its contact surface 49, see Fig. 11. It is evident at this that the said extension for the rest of the L-shaped leg extends on a level corresponding or higher than the highest level of the flanging 9 or the flange 20 or position but the squeezing of the filter 3 between the holding means 5 and the flanging 9 or its contact surface 49 is compensated well of the angled part 48 in the direction of the flanging 9. In Fig. 8 is shown a frame profile 14 for a frame 2 and with flange 20 and flanging 9 and which is preferably shaped of aluminium. Four profile parts are arranged in form of a frame to form a frame 2, which is provided with holding means 5, fastening arms 7 or said parts 24 for fasten a filter 3 to the frame 2. For an improved anchoring of the filter to the frame, the flanging 9 or the contact surface 49 can show grooved surface 18 or similar. Further, it is evident that the frame profile 14 is shaped with an angled corner 42 forming a more aerodynamic surface in the inlet of the arrangement, frame 2 or filter. Examples on filters 3, which can be in question in the arrangement in accordance with the invention are evident from, for example Figs. 4 - 6. The exemplified filters 3 show a first end part 31 and a second end part 32, whereby the first end part 31 is meant to be brought into engagement with the frame 2. Further, the first end part 31 can be shaped or provided with a connecting part 46, which according to one embodiment is produced by means of application of heat and pressure along the first end part 31 or border 33, whereby a band-shaped part exists in the filter 3, which shows a more stiff shaping and has a less or substantially lesser wall thickness. The connecting part 46 is thus shaped in such a way that it become stiffer than the filter material 30 itself, which, besides the prior mentioned method with the application of heat and pressure, can be effected by means of some means, such as by a sewing method, knitting or the like with thread or fabric, supplying of a medium, such as glue, etc. According to an additional embodiment of the filter 3, which is included in the arrangement according to the invention, the filter is provided with stiffenings 36, which can be produced in the same manner as the connecting part 46 or preferably by means of that fact that heat and pressure are applied to the filter 3 or the filter material 30. Such stiffenings 36 replace such prior mentioned and generally existing metal rods, which are arranged to extend in the folds of the filter 3 or in the opening edges to the pockets 34 in the opening 10 in the frame 2, which are of some length, and to extend between the frame or profile parts 14. Further, it is attained that the edges of the pockets 34 in the inlet end of the filter will be less voluminous, better suited for reducing disturb- ance of currents or give a minimum of air resistance for that air, which is going to be filtrated, purified, treated or similar. Moreover, the stiffenings 36 result in that surfaces are avoided where impurities can be collected, for example metal chips, besides other generally existing contaminations and particles in that air, which is going to be filtrated, whereby a blasting effect is prevented. The air flow forms otherwise the easy formable filter material 30 in such a way that the inlet opening to the filter, i.e. the opening edges to the pockets 34 and of some length become flattened and forms surfaces against the air flow. In order to shape the filter.3 more stiffer can corresponding stiffenings also be applied along the other end parts 32 of the filter 3 and further along the rest of the edge parts. To i.a. facilitate the mounting and the anchoring of the filter 3 to the frame 2 can the filter 3, its said first end part 31 or said border 33 be provided or is provided with stiffenings 35 in form of individual elements, for example shaped of plastic, see Figs. 5 and 13. Preferably, it exist four such stiffening elements 35, for example, arranged in the same distance with one another or one in each corner of the filter 3. The stiffening elements 35 can show grips 37 and/or hole 47 or press parts. As has been indicated above the stiffening elements 35 can be arranged to the filter 3 at its mounting in the arrangement or to the frame 2 or be included in the filter and facilitates by that the introduction of the filter 3 around the flanging 9 of the frame 2. At this, said grips 37, 47 are utilized with which hand grip, turnb grip or finger grip is taken and the stiffening elements 35 -are pressed towards the frame 2 and in the direction of its said surface 11. The stiffening elements 35 shall in this connection be regarded as aid means in the anchoring of a filter 3 to the frame 2. According to one embodiment of the stiffening elements 35, which in applicable cases are included in the filter 3, which is included in the arrangement in accordance with the invention, the stiffening elements 35 shows locking elements 38 in form of a flange, projecting edge or the like, which is meant to grasp behind the free edge 19 of the flanging 9 in the corner parts of the flanging 9. Thus, the stiffening elements 35 are brought with the locking elements 38 around the flanging 9 at its corner parts so that the locking elements 38 can snap, hook or the like behind the free end edge 19 of the flanging 9. Preferably, the stiffening elements 38 are shaped as a substantially angel-shaped element, whereby the locking element' 38 can be formed by a material portion, which extends between the angles in the stiffening element 35 in its inner angle. According to an advantageous embodiment of the arrangement in accordance with the invention the filter 3 is provided with a casing 4, which is meant to form a wrapping for the used filter 3. One embodiment of such a casing 4 is evident from Fig. 6, whereby the casing 4 according to another embodiment is attached to the filter 3 by means of attachment means 50, for example in form of a seam, glue, melting of the materials, weld or another attachment means, which in turn results in a more stiffer filter. The casing 4 shows a length exceeding the length of the filter 3 and has a first opening 43 and a second opening 44. As it is evident from Fig. 6 the first opening 43 of the casing 4 exists in connection with the opening of the filter 3, which has been produced by the fact that the end part 45 of the casing 4 has been folded back over the casing 4 and/or the filter 3. When a used filter 3 is going to be taken charge of that end part 45 is folded out so that the casing 4 adopt its complete length, whereby the contamined or polluted filter 3 can be wrapped up into the casing 4. The procedure for the wrapping is that that the open casing 4 is closed in the end parts and according to one embodiment of the arrangement in accordance with the invention the closing is done by particular closing devices 40 - 41, which includes a closing cord 41, which shall run in or on the casing 4 arranged or provided running devices 40. For the locking of the closing cord 41 exists a specially locking means. In order to be able to have the casing 4 closed tight, it may not exist any material or only exist a iriinimum of material in the closing devices 40, 41, i.e. they must consist of so little material as possible. The circumference of the casing 4 is considerable and therefore it is a long distance for the locking cord 41 to glide. If there is too much material in the closing devices, for example a closing cord running in a channel, so form that channel too much material. The more one is going to draw together the casing 4, the more difficult is it to success to get the casing tight by the folds and accumulations of material arising. In reality it is not possible to close the casing 4 tight with customary, simple and on the spot easy handled closing devices. Further, one has the problem with that friction arising due to the long pulling length for a closing cord against a surrounding material, as in a channel. According to one embodiment of the invention such problems have been solved by that fact that one has arranged perforations through the material of the casing 4 in the end parts 45 of the casing 4, for example in form of in rows after one another arranged holes 40, or coring-out of material in the material of the casing 4. The closing cord 41 is arranged to pass through these perforations 40 alternating on the exterior of the casing 4 and the interior.of the casing, i.e. the cord will have a zig-zag extens- ion or the like in its extension through the casing 4, see Fig. 14. By means of such a proposed closing device it is achieved a serviceable closing device, which fulfils the demands in a tight-fitting of the casing 4, is not dependent on accurate tolerances and besides can be attached to a low cost and in a simple and rational manner. When a frame 2 with a filter 3 is arranged in an installation device 1 in an air treatment plant, the casing 4 can be arranged in the arrangement or to the filter in such a way.that the casing 4 guides the air current towards the filter 3. By this it is attained a linear flow of that air, which shall pass the filter besides the said guiding of the air flow. Without exceeding the scope of the concept of the invention, modifications of the arrangement should be possible. Thus, the holding means for the filter in the frame can show another shaping and construction and, for example, be shaped as rulers, which are connected for a joint adjustment. Further, the filter can show another shaping and be without said stiffen¬ ings even if it should involve worse air treatment. The shaping of the casing can also be different but it is essential for removal of risks for contamination that a used and contamined filter is handled in a proper way. Thus, the filter with the filter-frame and the casing can, in the arrange¬ ment according to the invention, be lifted out from the installation device without that the contamined filter need to be touched or will come into contact with the siirrounding environment. With reference to, for example Fig. 9 and in this connection seen with an arranged filter with the belonging casing arranged to the frame, so can the filter be arranged beside to the installation device by grasping handles, which exist on the frame and which have not exist in that duct where contamined air flows, whereby the holding means are folded and parts of them can form supporting legs for the arrangement during its handling. At this, the filter is at first unfasten in the lower part of the frame. When the casing is half closed the filter is completely unfasten from the frame, whereby an absolute closing of the casing can happen, which closing is carrying out to the full by means of the locking devices and without that the filter need to be touched. The arrangement is thus not restricted to what has been described and shown in connection with the embodiment examples but soley by the following claims.

Claims: Claims : 1. Arrangement in air treatment plants showing installation devices ( 1) in order to hold one or more frames (2) for filters (3) , whereby the arrange¬ ment comprises a frame (2) , a filter (3) connectable with the frame (2) and a casing (4 ) , which is. meant to reach around the filter (3) , charac¬ terized in that the frame (2) shows holding means (5) to hold and/or anchor the filter (3) to the frame (2) and that the filter (3) is provided with stiffenings (35, 36) and the casing (4) with closing devices (40 - 41). 2. Arrangement in accordance with claim 1, characterized in that the frame (2) shows surfaces (11) turned towards the filter (3), the holding means (5) are arranged to run as tightening means along the surfaces, whereby the holding means (5) comprise pivotable arranged fastening arms (7) , whereby the fastening arms (7) or parts of them can in applicable cases form supporting legs in the arrangement when they are in a turned position in relation to the frame. 3. Arranganent in accordance with claim 2, characterized in that from the opening (10) of the frame (2) extends a flanging (9) in the direction of said surfaces (11) and is at an angle to said surfaces (11). 4. Arrangement in accordance with claim 3, characterized in that said fastening arms (7) are arranged to be able to be pivoted in the direction of the said flanging (9) and by that anchor the filter (3) to the frame (2) by squeezing between the fastening arms (7) and the flanging (9). 5. Arrangement in accordance with claim 1, 2 or 4, characterized in that the holding means (5) comprises parts, such as fastening arms (7) , which are arranged to extend along a surface (11) shown by the frame (2) , which surface in its turn extends around a flange (20) surrounding the opening (10) of the frame (2). 6. Arrangement in accordance with claim 1, characterized in that the holding means (5.) comprise legs or arms, whereby at least one leg is arranged to extend in the arrangement or the holding means (5) so a prestressing is attained. 7. Arrangement in accordance with claim 1 or 6, characterized in that the filter (3) shows pockets (34 ) , which are provided with stiffenings (36) arranged by influence of the filter material (30) by means of heat and pressure. 8. Arrangement in accordance with claim 1, 6 or 7, characterized in that one end part (31) of the filter is provided with stiffenings (35) in form individual elements. 9. Arrangement in accordance with claim 1 or 8, characterized in that the filter shows a first end part (31), which is arranged with or shows a border (33) , to which stiffenings (35) are arranged at a distance from one another, preferably four stiffenings (35) arranged, for example, in the same distance with one another. 10. Arrangement in accordance with claim 1, characterized in that the casing (4) shows a first opening (43) and a second opening (44), which openings (43, 44) are located in the end parts (45) of the casing (4), which end parts show closing devices (40, 41). 11. Arrangement in accordance with claim 1 or 10, characterized in that the closing devices (40, 41) comprise one or more closing cords (41) or similar, which are arranged to run in the casing (4) or through perfor¬ ations (40) arranged in the casing (4). 12. Arrangement in accordance with claim 1 or 10, characterized in that when a frame (2) with a filter (3) is arranged in an installation device (1) in an air treatment plant, the casing (4) is arranged in the device or to the filter in such a way that the casing (4 ) guides the air current towards the filter (3).

Inventors: HOEOEG NILS-ERIK, HOEOEG, NILS-ERIK
Applicants: GNG AIRFILTER SYSTEM AB, HOEOEG NILS ERIK, HOEOEG, NILS-ERIK
Application year: 1994
Main classification: B01D46
IPC codes: B01D46